128388887 has 16 divisors (see below), whose sum is σ = 149575680. Its totient is φ = 109048800.

The previous prime is 128388839. The next prime is 128388889. The reversal of 128388887 is 788883821.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 128388887 - 2¹⁸ = 128126743 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128388889) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3398 + ... + 16380.

It is an arithmetic number, because the mean of its divisors is an integer number (9348480).

Almost surely, 2^128388887 is an apocalyptic number.

128388887 is a deficient number, since it is larger than the sum of its proper divisors (21186793).

128388887 is a wasteful number, since it uses less digits than its factorization.

128388887 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13054.

The product of its digits is 1376256, while the sum is 53.

The square root of 128388887 is about 11330.8820045043. The cubic root of 128388887 is about 504.4782861565.

The spelling of 128388887 in words is "one hundred twenty-eight million, three hundred eighty-eight thousand, eight hundred eighty-seven".